Different techniques to evaluate catalytic activity and to quantify residual service life (RSL) have been applied to DSA(R) anodes used in chlor-alkali industrial cells. An accelerated service life test in sulfuric acid was used as a reference method. The results obtained through EIS, cyclic voltammetry and Ru content analysis of the catalytic layer confirm the results obtained with the accelerated test. There is a direct relation between the residual service life (RSL) thus obtained and the catalytic properties of the electrode. The different mechanisms of catalytic activity loss are discussed. An evaluation methodology is proposed to reduce maintenance costs of industrial cells.